OneDrive from Microsoft is a cloud storage and file syncing service.

Cloud storage sites where you can upload files, sync files saved on your computer to the cloud as backup, as well as use the sites to share files with others as an alternative to emailing (particularly useful for large files), as well as provide spaces where others can share large files with you.
OneDrive from Microsoft is a cloud storage and file syncing service.
Box is an online file sharing, content management, and collaboration service.
Dropbox is a file syncing and sharing, cloud storage service.
Google Drive is a cloud storage and file syncing service. Google Drive also includes Google Docs, Google Sheets, and Google Slides, which are a part of an office suite you can use for collaborative editing of documents, spreadsheets, presentations, drawings, forms, and more. Files created and edited through the office suite are saved in Google Drive.
Sync.com is a file syncing and sharing, cloud storage service.